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| author | Sander de Smalen <sander.desmalen@arm.com> | 2025-07-10 15:30:02 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-07-10 15:30:02 +0100 |
| commit | 362d5ffa8d2f521fc2912665270eba15f3c1bf56 (patch) | |
| tree | 503f23cc799fa6da12960bc4366f2597d64517ef /llvm/lib/CodeGen/TargetInstrInfo.cpp | |
| parent | f56b6ecf088ef46fe8008f294fff456805b33a07 (diff) | |
| download | llvm-362d5ffa8d2f521fc2912665270eba15f3c1bf56.zip llvm-362d5ffa8d2f521fc2912665270eba15f3c1bf56.tar.gz llvm-362d5ffa8d2f521fc2912665270eba15f3c1bf56.tar.bz2 | |
[CodeGen] commuteInstruction should update implicit-def (#131361)
When the RegisterCoalescer adds an implicit-def when coalescing
a SUBREG_TO_REG (#123632), this causes issues when removing other
COPY nodes by commuting the instruction because it doesn't take
the implicit-def into consideration. This PR fixes that.
Diffstat (limited to 'llvm/lib/CodeGen/TargetInstrInfo.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/TargetInstrInfo.cpp | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/TargetInstrInfo.cpp b/llvm/lib/CodeGen/TargetInstrInfo.cpp index 8b82deb..660a1a4 100644 --- a/llvm/lib/CodeGen/TargetInstrInfo.cpp +++ b/llvm/lib/CodeGen/TargetInstrInfo.cpp @@ -238,7 +238,14 @@ MachineInstr *TargetInstrInfo::commuteInstructionImpl(MachineInstr &MI, } if (HasDef) { - CommutedMI->getOperand(0).setReg(Reg0); + // Use `substituteRegister` so that for a case like this: + // %0.sub = INST %0.sub(tied), %1.sub, implicit-def %0 + // the implicit-def is also updated, to result in: + // %1.sub = INST %1.sub(tied), %0.sub, implicit-def %1 + const TargetRegisterInfo &TRI = + *MI.getMF()->getSubtarget().getRegisterInfo(); + Register FromReg = CommutedMI->getOperand(0).getReg(); + CommutedMI->substituteRegister(FromReg, Reg0, /*SubRegIdx=*/0, TRI); CommutedMI->getOperand(0).setSubReg(SubReg0); } CommutedMI->getOperand(Idx2).setReg(Reg1); |